There has been developed an optical torque measurement device for detecting a torque of a drive axis (rotating body) in rotating equipment such as a gas turbine and a steam turbine, for the purpose of identifying a cause of change in a thermal efficiency of a combined-cycle generating plant or a steam turbine plant, for example. This torque measurement device provides a pair of reflectors at different positions on the rotating body in the axial direction thereof, irradiates both of the reflectors with laser light and detects reflected light thereof from both of the reflectors, obtains a rotation period of the rotating body from periodical strong and weak intensities of the reflected light, and detects a torque of the rotating body from a delay time of the reflected light between the reflectors (refer to Patent document 1, for example).
In such a torque measurement device, extraction of the reflected light data necessary for signal processing, yes-no judgment of a processed result in the signal processing, or the like, is operated manually by an analyzer and takes a long time for the analysis job thereof. Accordingly, there is a technique that specifies a reflection pattern position of the reflected light reflected by the reflector, which is provided to the rotating body, automatically using a signal processing device, calculates the rotation period or a twist amount of the rotating body from data within a reflection pattern range determined by the specified reflection pattern position, automatically using the signal processing device, and calculates the torque from the calculated twist amount of the rotating body (refer to Patent document 2, for example).
Patent document 1: Japanese Unexamined Patent Application Publication No. 2002-22564
Patent document 2: Japanese Unexamined Patent Application Publication No. 2005-16950